Selector-switch.



O. F. FORSBERG.

SELECTOR SWITCH.

APPLICATION FILED SEPT. 13, 1915. 1,182,363. Patented May9,1916.

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Oscar f Fansberq STATES PATENT onion.

OSCAR F. FORSBERG, YONKERS, NEW YORK, ASSIGNOR, BY MESNE ASSIGNMENTS,

TO WESTERN ELECTRIC COMPANY, INCORPORATED, A CORPORATION NEV YORK.

SELECTOR-SWITCH.

Application filed September 13, 1915.

To all whomjt may concern Be it known that I, OSCAR FERDINAND Fonsnnno,a citizen of the United States, residing at Yonkers, in the county ofWestchester and State of New York, have invented certain new and usefulImprovements in Selector-Switches, of which the following is a full,clear, concise, and exact description.

This invention-relates to automatic selector switches such as are usedin telephone exchanges.

Its object is to provide a switch having a single set of brushes capableof serving a large number of lines and wherein connection may be quicklymade to any of such lines. I

The switch of thisinvention comprises a vertical row of terminals at thetop of which a. brush, mounted on a suitable carrier, normally rests,which brush is adapted to wipe over said terminals in long and shortsteps under the influence of gravity. The distance the brush is allowedto drop is determined by the number of impulses received by a magnetcontrolling an escapement mechanism for the brush carrier.

The escapement mechanism may comprise a pair of escape wheels. a doublepawl operating therewith and an escape magnet, one escape wheel having agreater number of teeth than the other, these wheels being fixedto ashaft carrying a pinion engaging a rack on the, brush carrier. The shaftis moved axially by a shift magnet so that one or the other escape wheelcooperates with the double pawl of the escapement depending upon whetherthe brush is to drop long steps or short steps for each operation of theescape magnet. The brush is elevated to the top of the row upondisestablishment of the connection by a stepping magnet.

Referring to the drawings, Figure 1 is a side elevation of a switchconstructed in ac cor-dance with this invention with the front plateremoved and portions broken away, and Fig. 2 is a section on line 22 ofFig. 1.

The terminals 10 maybe assembled in sets in a panel as shown in U. S.Patent No. 1,127,741. These terminals are multiplied horizontally acrossthe face of the panel so as to be accessible to a number of elevatormechanisms 1.1 each carrying a set of brushes 12. The brush sets may beconstructed as shown in U. S. Patent 1,123,696.

Specification of Letters Patent.

Patented May 9, 1916.

Serial No. 50,544.

Mounted on suitable bearings'30, 31 in the frame 13 is a shaft 14. Thisshaft is free to move axially a limited distance as well as to rotate.Rigidly mounted upon this shaft are two escape wheels 15, 16. The wheel15 has a number of teeth 17, and the wheel 16 has one tooth 18 for everyten teeth of wheel 15. The carrier 11 has a rack 22 meshing with apinion 21 loosely mounted on shaft 14.

When the magnet 20 of the escapement mechanism is energized, the weightof the carrier rotates the pinion 21, which, acting through the pawl 32fixed to wheel 16, rotates said wheel until the tooth 34 of wheel 15engages the upper end of the double pawl 35, the wheel 15 being normallyheld in en gagement with pawl 35 by a spring 38 (Fig. 2). When magnet 20denergizes, spring 36 disengages the upper end of pawl 35 from tooth 34,and the movement of wheel 15 is arrested when the lower end of pawl 35engages tooth 37. Thus, each time magnet 20 is energized anddeenergized, it allows the ratchet Wheel 15 to rotate one step and thebrushes 12 to drop a distance equal to the space between two sets ofterminals 10. The escape magnet 20 may be operated by a stepping relay,this relay being operated from a suitable sender in any well-knownmanner when the switch is used as a connector, or in case it is used asa trunking switch, such magnet may be controlled locally as well as by asender. A magnet 23 mounted on frame 13 is adapted by means of itsarmature 24 to shift shaft 14 axially against the tension of spring 38so that the pawl 35 of the escapement mechanism cooperates with ratchetwheel 16 instead of with wheel 15. Now for each energization anddeenergization of magnet 20, magnet 23 being maintained energized, theescapement mechanism allows the brushes 12 to drop a distance equal tothat between ten sets of terminals 10. The magnet 23 is connected to acircuit-changing device (not shown), such, for example, as a sideswitch, which at the proper time closes its circuit to effect thischangeover operation in any well-known manner. This magnet 23 will be'operated before the magnet 20, if the group containing the wanted lineis not the top one. At the conclusion of the conversation a circuit isclosed through magnet 25 including an interrupting machine. The pawl 27carried by the armature 26 of this magnet engages the teeth 28 on therack 22, driving the brush carrier 11 upwardly. During this upwardmovement of the carrier, the pinion 21 rotates on the shaft 14 and thepawl 32 slips over the teeth 33 thereof. The circuit of magnet is openedwhen the brushes l2 reach their normal position at the top of the anel.

WVhat is claimed is:

1. In an automatic selector switch, the combination with a vertical rowof terminals, a carrier having a brush normally resting at the top ofsaid row, means including a magnet for allowing said brush to drop inlong and short steps over said row, and a stepping magnet adapted toelevate said brush carried to its normal position.

2. In a selector, the combination with a vertical row of terminals, acarrier having a brush normally resting at the top of said row, meansfor allowing said brush to drop in long and short steps comprising ashaft, a pair of escape wheels fixed thereto, one having a greaternumber of teeth than the other, a detent adapted to cooperate with oneor thecther of said wheels, a magnet controlling said detent and amagnet adapted to control the relation of said wheels to said detent,and means for restoring said carrier.

In a selector, the combination with a vertical row of terminals, acarrier having a brush normally resting at the top of said row, meansfor allowing said brush to drop in long and short steps comprising ashaft, hearings therefor, pair of escape wheels fixed to said shaft, onehaving a greater number of teeth than the other, a double pawl adaptedto cooperate with one or the other of said wheels, and a magnetcontrolling said double pawl, a magnet adapted to shift said shaftaxially in said hearings to cause one or the other of said wheels to cooperate with said double pawl, and means for restoring said carrier.

In witness whereof, I hereunto subscribe my name this 10th day ofSeptember A. D.,

OSCAR F. FORSBERG.

